PRODUCTION PACKAGE FOR JACKFRUIT

Haripriya,S

Assistant Professor (Horticulture), Tamil Nadu Agricultural University, Coimbatore

Jackfruit (Artocarpus heterophyllus) of Moraceae family is one of the most significant trees in tropical home gardens. Jackfruit tree is native to the rainforests of Malaysia and the Western Ghats of India. Introduced to most Pacific islands, the tree can be found throughout the Pacific, primarily in home gardens, where it finds a place among other favourite multipurpose plants.

The jackfruit is adapted only to humid tropical and near-tropical climates. The jackfruit tree flourishes in rich, deep soil of medium or open texture. It cannot tolerate water lodging, as the tree will not bear fruit or may die. It is a medium-sized evergreen tree that is easily recognized by its fruit, largest tree-borne fruits in the world. Flowers are monoecious, having male and female inflorescences or spikes on the same tree. Pollination is by insects and wind, with a high percentage of cross-pollination. It bears a compound or multiple fruit with a green to yellow-brown exterior rind that is composed of hexagonal, bluntly conical carpel apices that cover a thick, rubbery, whitish to yellowish wall.

The 'Singapore', or 'Ceylon', jack, a remarkably early bearer producing fruit in 18 months to 2 ½ years from transplanting, was introduced into India from Ceylon and planted extensively in 1949. In 1961, the Horticultural Research Institute at Saharanpur, India, reported the acquisition of air-layered plants of the excellent varieties, Safeda, Bhusila, Bhadaiyan, Handia and others. The Fruit Experimental Station at Burliar, established a collection of 54 jackfruit clones from all jackfruit producing countries and ultimately selected 'T Nagar Jack' as the best in quality and yield. Vegetable Research Station, Palur released PLR- 1 is an off-Season bearing, high yielding (79 fruits weighing 890Kg/tree/year) and suitable for high density planting. In 1996, a Hybrid jack was developed by crossing Singapore Jack and Velipala at Fruit Research Station, Kallar. By 2007, Jackfruit variety PLR- 2 was released, which has highly palatable and edible flakes, the fruit yield per tree per year would be 95 to 110 in numbers.  Velipala, Singapore, Hybrid jack, Panruti selection, Thanjavur jack, Burliar 1, PLR 1 and PPI 1 (Peechiparai-1) are the popular varieties in jack.

Exotic varieties of Jackfruit:

 Based on the season of its fruit bearing nature, jackfruit trees can be broadly classified into,

Propagation is usually by seeds which can be kept no longer than a month before planting. Germination requires 3 to 8 weeks but is accelerated by soaking seeds in water for 24 hours. Grafting can be carried out throughout the year. However, veneer grafting is more successful during spring and summer (March to May) and is the most commercially exploited method of grafting followed in Jackfruit. The availability of mature and dormant scions is a pre- requisite for successful grafting. Grafting involves the union of a shoot, called a scion, from a selected superior phenotype and a compatible rootstock from a desirable plant. The seeds of the rootstock were raised in a 25 x 20 cm size polybags and the healthy ones were used as rootstocks for grafting. A shallow cut about 6–8 cm long should be made in the rootstock, slanting inward to about a quarter of the diameter of the stem, at the point of active growth or where the bark separates easily from the wood. A short, second downward oblique cut should then be made at the base of the first, removing a piece of bark and wood. The scions should be 5 –15 cm long, 1 cm in diameter (pencil thickness), mature and dormant. The scions were collected from the terminal shoots with several plump unopened buds of matured trees that have already started to bear fruits. Select and cut 5–15 cm long scions from the mother tree, and remove leaves immediately with a sharp knife, retaining the petioles.  Put scions in a closed polythene bag or in clean water contained in a polythene bag to prevent desiccation and keep them fresh. The scions may be kept like this for several days, but the best rate of success is obtained with freshly severed scions. Insert the scion into the rootstock seedling and then wrap the union portion with thin polythene strip and the top portion of the graft may be covered with a polythene cap, the grafts to be were then kept in a mist chamber. It may take about 2–3 weeks for complete union of the scion with the rootstock. At this stage, dormant buds will sprout and the cap can be removed. When the leaves are green, the grafts are transferred to an open nursery for hardening, before ready to be planted in the orchard.

Planting may be done, preferably grafts during June to December at 8 x 8 m spacing. Digging pits of 1 m x 1 m x 1 m dimension and were filled with top soil mixed with 10 Kg of farm yard manure and 1 Kg of neem cake per pit.  Apply Lindane 1.3% @ 100 g/pit and mix it thoroughly. The tree grows moderately rapidly in early years, up to 1.5 m/yr
(5 ft/yr) in height, slowing to about 0.5 m/yr (20 inches/yr) as tree reaches maturity.

Organic manures and fertilizers (kg/tree) should be applied in two splits during May to June and September to October.

Pruning is not commonly practised in Jackfruit. Non-pruned seedling trees generally develop a strong central leader, which is desirable for its timber value. However, grafted trees exhibit dwarfing tendency and branch very early in their growth. These branches need to be pruned continuously to achieve a reasonably productive trunk. Thereafter, branches may be allowed to grow at desired intervals. The inner branches of the canopy may be removed to allow more light and air within the canopy. Regular pruning of weak, dead and diseased branches and removing all parasitic plants at the end of the rainy season may prevent insect infestation and disease infection. Tree height and canopy size may also be controlled, if desired, through pruning.

In Asia, jackfruits ripen principally from March to June, April to September, or June to August, depending on the climate, with some off-season crops from September to December, or a few fruits at other times of the year. Fruits mature 3 to 8 months from flowering. After harvesting, the fruiting twigs may be cut back to the trunk or branches to induce flowering in the next season. The fruits may be covered with paper sacks when very early during initiation of fruit development stage to protect them from pests and diseases. The bags encourage ants to swarm over the fruit and guard it from its enemies.

Fruit maturity indications include hollow sounding when tapped; spines become flattened and wider; colour of fruit becomes pale; develops a strong aroma and matures 3 to 8 months after flowering. Harvesting of fruits may be done by cutting off the footstalk and lowering the fruits carefully, without dropping on the ground which may damage them. Collect fruits in a basket and lower them to the ground using a rope.  The portion of the stalk attached to the fruits helps in handling.  Harvest fruits in the morning hours while temperatures are low and transfer immediately to a well-ventilated shed.

The economic or remarkable fruit yield commences from 5^th year in grafts and 8^th year in seedling trees. In India, a good yield is 150 large fruits per tree annually, though some trees bear as many as 250 fruits and a fully mature tree may produce 500, these probably of medium or small size. An average of 50-80 tons fruit/ ha can be harvested.

Jackfruit is a climacteric fruit with a short shelf life, which quickly becomes unfit for human consumption. Jackfruits turn brown and deteriorate quickly after ripening. During harvesting, the fruit is sometimes allowed to fall and must be collected daily as it has a shelf life of only a few days. The ripened fruit flakes can be cryo-frozen by placing the fruit flakes in cans containing 40% sugar syrup and 0.5% citric acid at -180C for 6 months without the colour and sensory qualities being affected. Cold storage trials indicate that ripe fruits can be kept for 3 to 6 weeks at 11°-12.5°C and relative humidity of 85 to 95%.

Plant Protection practices:

1. Bud Weevil (Ochyromera artocarpi)

The small whitish grubs of bud weevil bore into tender flower buds as well as fruits and induce premature drop. The adult weevils are greenish brown in colour and are found to eat the leaves.

Remedy :

• Remove the infested shoots, flower buds and fruits to check infestation.

2. Shoot and fruit borer(Diaphania caesalis )

Among insect pests, the shoot and fruit borer, Diaphania caesalis, is a major pest of  jackfruit. The insects lay eggs on tender shoots and flower buds. On hatching, the reddish brown larvae bore into shoot, flower buds and fruits, resulting in the wetting of affected parts. Larvae make small holes and enter the fruit.  At the initial stage of damage, a small hole with fresh excreta can be seen. Gradually the hole is extended and at a later stage fungal infection occurs.  Tender fruits may drop under severe infestation, leading to losses of 30%.

Remedy

• To protect them from egg laying, fruit may be covered with polythene bags and the affected parts removed and destroyed.  
• Infestation may be checked naturally if the trees are regularly pruned of dead and diseased twigs and small shoots within the canopy, to allow sufficient light and air to pass through. Pruning may be done soon after harvest or at the end of rainy season.
• Spraying of carbaryl @ 4 g per litre of water during flowering may be recommended.

3. Bark Borer (Indarbela tetraonis and Batocera spp.)

Bark borer bore holes in the bark and feed on the cambium layer, gummy exudation would evidenced on the outer portion of the affected tree.

Remedy

• Remove the dead branches where it lays its eggs.
• Bum affected twigs and dead branches.
• Clean the bark portion, insert a cotton ball soaked in kerosene into the hole and seal the hole with mud.

DISEASES

1. Blossom rot, fruit rot or stem rot (Rhizopus artocarpi)

It was a serious disease, which causes 15 to 32% crop loss. The inflorescence, tips of the flowering shoots or the stalk of the tender fruits are infected and blackened by fungal structures called sporangia. Flowers and fruits rot and drop prematurely.

Remedy

• Collect and destroy the fallen leaves and fruits under the tree.
• Spray 1 % Bordeaux mixture or Copper oxy chloride 2.5 g/lit. Three sprays must be given at 15 days interval.

2. Leaf Spot (Phyllosticta artocarpina)
Light brown with double margin spots are prominent on leaves. Such leaves defoliate and give barren look to the trees.
Remedy
Spray 1 % Bordeaux mixture